assertTrue(Thread.holdsLock(mutex));
      return super.toString();
    }

    @Override
    public boolean equals(@Nullable Object o) {
      assertTrue(Thread.holdsLock(mutex));
      return super.equals(o);
    }

    @Override
    public int hashCode() {
      assertTrue(Thread.holdsLock(mutex));
      return super.hashCode();
    }

    @Override
    public int size() {

      super(message);
    }

    public ExceptionWithManyConstructorsButOnlyOneThrowable(
        String message, String a1, String a2, String a3) {
      super(message);
    }

    public ExceptionWithManyConstructorsButOnlyOneThrowable(String message, Throwable antecedent) {
      super(message);
      this.antecedent = antecedent;
    }

    public ExceptionWithManyConstructorsButOnlyOneThrowable(

  @Override
  public void testContainsKey() {
    try {
      super.testContainsKey();
    } catch (ClassCastException tolerated) {
    }
  }

  @J2ktIncompatible // https://youtrack.jetbrains.com/issue/KT-58242/ undefined behavior (crash)
  @Override
  public void testEntrySetContainsEntryIncompatibleKey() {
    try {
      super.testEntrySetContainsEntryIncompatibleKey();
    } catch (ClassCastException tolerated) {

    Builder(int initCapacity) {
      super(initCapacity);
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> put(K key, V value) {
      super.put(key, value);
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
      super.put(entry);
      return this;
    }

  @Override
  public void testEntrySetRemoveAllNullFromEmpty() {
    try {
      super.testEntrySetRemoveAllNullFromEmpty();
    } catch (RuntimeException tolerated) {
      // GWT's HashMap.entrySet().removeAll(null) doesn't throws NPE.
    }
  }

  @Override
  public void testEntrySetRetainAllNullFromEmpty() {
    try {
      super.testEntrySetRetainAllNullFromEmpty();
    } catch (RuntimeException tolerated) {

final class TableCollectors {

  static <T extends @Nullable Object, R, C, V>
      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(
          Function<? super T, ? extends R> rowFunction,
          Function<? super T, ? extends C> columnFunction,
          Function<? super T, ? extends V> valueFunction) {
    checkNotNull(rowFunction, "rowFunction");
    checkNotNull(columnFunction, "columnFunction");

  public TestWriter(TestOutputStream out) {
    super(new OutputStreamWriter(checkNotNull(out), UTF_8));
    this.out = out;
  }

  @Override
  public void write(int c) throws IOException {
    super.write(c);
    flush(); // flush write to TestOutputStream to get its behavior
  }

  @Override
  public void write(char[] cbuf, int off, int len) throws IOException {
    super.write(cbuf, off, len);
    flush();
  }

    public Chars() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super('b', 'a', 'c', 'd', 'e');
    }
  }

  public static class Enums extends SampleElements<AnEnum> {
    public Enums() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super(AnEnum.B, AnEnum.A, AnEnum.C, AnEnum.D, AnEnum.E);
    }
  }

    public Chars() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super('b', 'a', 'c', 'd', 'e');
    }
  }

  public static class Enums extends SampleElements<AnEnum> {
    public Enums() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super(AnEnum.B, AnEnum.A, AnEnum.C, AnEnum.D, AnEnum.E);
    }
  }

    super(map);
  }

  @Override
  public SortedMap<K, Collection<V>> asMap() {
    return (SortedMap<K, Collection<V>>) super.asMap();
  }

  @Override
  SortedMap<K, Collection<V>> backingMap() {
    return (SortedMap<K, Collection<V>>) super.backingMap();
  }

  @Override
  public SortedSet<K> keySet() {
    return (SortedSet<K>) super.keySet();
  }

  @Override